October is expected to be a big sales month for General Motors. The automaker will reportedly announce the first year-over-year sales gain in 21 months, CNNMoney.com reports.

When manufacturers announce their October sales figures next week, GM is also expected to announce that it has gained market share for the third month in a row, said GM executive director of corporate planning, Mike DiGiovanni.

Comparing September 2009 to September 2008, GM’s sales were down 45%. Although the cash for clunkers “hangover” affected GM last month, its rival, Ford, did much better in September, with a sales decline of only 5.1% compared to September of last year. Foreign automakers like Hyundai and Kia saw an increase of 27% and 24% in September.

GM expects its vehicle sales will amount to 20% to 21% of all vehicles sold in October, DiGiovanni said. These figures are expected to be about 3% higher than Toyota’s and 4% higher than Ford’s, he said.

“When you look at GM’s performance, we’re having a really good October,” DiGiovanni said.

After a failed attempt to sell its Saturn brand and its auto financing arm, GMAC, asking for more government aid, GM needs some positive news for once. October’s sales could bring just that.